March 8, 2017 | News
A low-cost, nonflammable battery with a high energy density and the capability of thousands of more recycling cycles than any comparable battery to come out of a laboratory has been developed by researchers at The City University of New York’s Energy Institute.
In research published in the journal Nature Communications, the Energy Institute said the battery is in the same class as the familiar AA, but its energy density is potentially high enough to equal that of lithium ion batteries, without the danger.
Scaled up, it would allow electric utilities, commercial and residential buildings and homeowners to store electricity generated by solar and wind systems to provide power at night and when the wind isn’t blowing. Scaled down, it offers a safe alternative to widely used lithium ion batteries, which have caused fires in cell phones, airplanes and electric cars.
“Batteries for [power] grid applications such as integration of renewable power must be low cost, of high cycle life and energy density, safe, reliable and composed of easily acquired materials requiring relatively simple manufacturing processes,” the paper says. Previous technologies “are often unsuitable for wide [grid] deployment because of cost, durability and potential safety hazards.”
Senior research associate Gautam G. Yadav, the paper’s lead author and principal inventor, worked with senior research associates Joshua W. Gallaway, Damon E. Turney and Michael Nyce, doctoral students Jinchao Huang and Xia Wei, and Distinguished Professor of Chemical Engineering Sanjoy Banerjee, who directs the CUNY Energy Institute.
Their research culminates a prestigious $5 million grant from the federal Advanced Research Projects Agency-Energy, which supports the development of advanced energy technologies. Some of the research was conducted at Brookhaven National Laboratory.
Past researchers had achieved either high cycle life or what’s called “high areal capacity” – that is, packing a lot of battery electrodes into a small volume to increase energy density – but never both together. For example, one recent report achieved 5,000 cycles, but at only at a minuscule output of one milliamp hour per square centimeter (1 mAh/cm2) areal capacity. Another successfully achieved 26 mAh/cm2, but with only 60 recharging cycles. The CUNY battery leaves them in the dust by getting 6,000 cycles at 2.5 mAh/cm2 and 1,000 cycles at 28 mAh/cm2.
During three years of research involving thousands of experiments, the CUNY chemical engineers achieved both goals by intercalating (inserting) copper into a kind of manganese dioxide known as birnessite that had been modified with the metal bismuth. Ford Motor Co. discovered bismuth-modified birnessite in the 1980s while developing electric cars; although it allows for many recharging cycles, no one before had figured out how to use it at high areal capacity.
The paper says the manganese dioxide cathode provides “an exceptional combination of reversibility and very high capacity” when combined with copper ions in a lattice of layered birnessite. “The resulting composite material benefits from enhanced charge transfer and complete regeneration of layered materials on each cycle.” The battery also uses a commonplace zinc anode.
The paper adds that this methodology also could be used in “other areas where layered materials are of interest like oxidation catalysts, intercalation chemistry and membranes for removal of heavy-metal ions.”
CUNY has already licensed the new, higher-density battery to Urban Electric Power, a startup based in Pearl River, N.Y., which has begun manufacturing a lower-density version of this battery that is based on somewhat different technology. Last year the state Regional Economic Development Council awarded the company $1 million to equip its factory, expand its production staff and ramp up to an initial goal of manufacturing 30,000 batteries a year. The company says its next target will be expanding to a more automated plant with 10 times that capacity.